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Finding the Fourth Proportional to 718.87, 1,078.49 and 389.66

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Solution

The fourth proportional to 718.87, 1,078.49 and 389.66 is: 584.59

Step by Step Solution

  1. Step 1: Write the proportion equation
    718.87 : 1,078.49 = 389.66 : x
  2. Step 2: Convert to fraction form
    718.87/1,078.49 = 389.66/x
  3. Step 3: Cross multiply
    718.87x = 1,078.49 × 389.66
  4. Step 4: Simplify right side
    718.87x = 420,240.74
  5. Step 5: Solve for x
    x = 420,240.74/718.87
  6. Step 6: Final answer
    x = 584.59

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.